1 /* $OpenBSD: atomicio.c,v 1.30 2019/01/24 02:42:23 dtucker Exp $ */
2 /*
3 * Copyright (c) 2006 Damien Miller. All rights reserved.
4 * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
5 * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include "includes.h"
30
31 #include <sys/uio.h>
32
33 #include <errno.h>
34 #ifdef HAVE_POLL_H
35 #include <poll.h>
36 #else
37 # ifdef HAVE_SYS_POLL_H
38 # include <sys/poll.h>
39 # endif
40 #endif
41 #include <string.h>
42 #include <unistd.h>
43 #include <limits.h>
44
45 #include "atomicio.h"
46
47 /*
48 * ensure all of data on socket comes through. f==read || f==vwrite
49 */
50 size_t
atomicio6(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n,int (* cb)(void *,size_t),void * cb_arg)51 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
52 int (*cb)(void *, size_t), void *cb_arg)
53 {
54 char *s = _s;
55 size_t pos = 0;
56 ssize_t res;
57 struct pollfd pfd;
58
59 pfd.fd = fd;
60 #ifndef BROKEN_READ_COMPARISON
61 pfd.events = f == read ? POLLIN : POLLOUT;
62 #else
63 pfd.events = POLLIN|POLLOUT;
64 #endif
65 while (n > pos) {
66 res = (f) (fd, s + pos, n - pos);
67 switch (res) {
68 case -1:
69 if (errno == EINTR) {
70 /* possible SIGALARM, update callback */
71 if (cb != NULL && cb(cb_arg, 0) == -1) {
72 errno = EINTR;
73 return pos;
74 }
75 continue;
76 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
77 (void)poll(&pfd, 1, -1);
78 continue;
79 }
80 return 0;
81 case 0:
82 errno = EPIPE;
83 return pos;
84 default:
85 pos += (size_t)res;
86 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
87 errno = EINTR;
88 return pos;
89 }
90 }
91 }
92 return pos;
93 }
94
95 size_t
atomicio(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n)96 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
97 {
98 return atomicio6(f, fd, _s, n, NULL, NULL);
99 }
100
101 /*
102 * ensure all of data on socket comes through. f==readv || f==writev
103 */
104 size_t
atomiciov6(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt,int (* cb)(void *,size_t),void * cb_arg)105 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
106 const struct iovec *_iov, int iovcnt,
107 int (*cb)(void *, size_t), void *cb_arg)
108 {
109 size_t pos = 0, rem;
110 ssize_t res;
111 struct iovec iov_array[IOV_MAX], *iov = iov_array;
112 struct pollfd pfd;
113
114 if (iovcnt < 0 || iovcnt > IOV_MAX) {
115 errno = EINVAL;
116 return 0;
117 }
118 /* Make a copy of the iov array because we may modify it below */
119 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov));
120
121 pfd.fd = fd;
122 #ifndef BROKEN_READV_COMPARISON
123 pfd.events = f == readv ? POLLIN : POLLOUT;
124 #else
125 pfd.events = POLLIN|POLLOUT;
126 #endif
127 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
128 res = (f) (fd, iov, iovcnt);
129 switch (res) {
130 case -1:
131 if (errno == EINTR) {
132 /* possible SIGALARM, update callback */
133 if (cb != NULL && cb(cb_arg, 0) == -1) {
134 errno = EINTR;
135 return pos;
136 }
137 continue;
138 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
139 (void)poll(&pfd, 1, -1);
140 continue;
141 }
142 return 0;
143 case 0:
144 errno = EPIPE;
145 return pos;
146 default:
147 rem = (size_t)res;
148 pos += rem;
149 /* skip completed iov entries */
150 while (iovcnt > 0 && rem >= iov[0].iov_len) {
151 rem -= iov[0].iov_len;
152 iov++;
153 iovcnt--;
154 }
155 /* This shouldn't happen... */
156 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
157 errno = EFAULT;
158 return 0;
159 }
160 if (iovcnt == 0)
161 break;
162 /* update pointer in partially complete iov */
163 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
164 iov[0].iov_len -= rem;
165 }
166 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
167 errno = EINTR;
168 return pos;
169 }
170 }
171 return pos;
172 }
173
174 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)175 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
176 const struct iovec *_iov, int iovcnt)
177 {
178 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
179 }
180